[RESOLVED] Winsock closing before data gets sent

[Constantine]

I have two PCs connected using winsock (TCP), and before one of them disconnects my program sends a message to let the other end know that the connection is being killed. To do this, I have a very simple bit of code:

Private Sub BtnDisconnect_Click()
    If Sock1.State = sckConnected Then
        Sock1.SendData ("~disconnecting") 
    End If
    Sock1.Close
End Sub

However, the other computer never receives the message. If I remove "Sock1.Close" it works fine. I don't really have a clue what is happening. Is there any simple way to fix this problem?

[dynamic_sysop]

have you tried waiting until the Send_Complete triggers? eg:

'/// Boolean handler to determine when to disconnect.
Private DC_Sent As Boolean

Private Sub Command1_Click()
DC_Sent = False
'/// connect your socket

End Sub

Private Sub btnDisconnect_Click()
If sock1.State = sckConnected Then
 sock1.SendData ("~disconnecting")
 DC_Sent = True
End If
End Sub

Private Sub sock1_SendComplete()
If DC_Sent = True Then
    sock1.Close
End If
End Sub

[DigiRev]

As dynamic said, use the SendComplete() event. I've often written a WaitForSend() sub to help keep things simple if you have a lot of code that sends something before disconnecting.

Option Explicit
 
'Used so DoEvents is only called when needed.
Private Declare Function GetInputState Lib "user32" () As Long
 
Private bolSending As Boolean 'Sending data?
 
Private Sub WaitForSend()
    bolSending = True
    Do
        If GetInputState Then DoEvents
    Loop Until Not bolSending Or Winsock1.State = sckClosed Or Winsock1.State = sckError
End Sub
 
Private Sub Winsock1_SendComplete()
    bolSending = False
End Sub
 
'Then you can use the code like this:
Private Sub cmdSendBeforeClose_Click()
    Winsock1.SendData "~disconnecting"
    WaitForSend
    Winsock1.Close
End Sub

[Constantine]

Thank you both. The program is working properly now